Vapor-electric device



Sept. 5 1939. w. E. PAKALA 2,172,221

VAPOR-ELECTRIC DEVICE Filed Aug. 3, 1938 2 sheetsshet 1 INVENTOR 2 MW/omEPam/a.

W 4% BYJ? 4 fww ATTORNEY Sept. 5, 1939. w. E. PAKALA VAPOR-ELECTRIC DEVICE Filed Aug. 5, 1938 2 Sheets-Sheet 2 WITNESSES:

INVENTOR MY/fom 7 faKa/a.

ATTORNEY Patented Sept. 5, 1939 UNITED STATES PATENT OFFICE VAPOR-ELECTRIC DEVICE William E. Pakala, Forest Hills, Pa., assignor to Westinghouse Electric & Manufacturing Gompany, East Pittsburgh, Pa., a corporation of Pennsylvania Application August 3, 1938, Serial No. 222,799

6 Claims.

My invention relates to a vapor-electric device and particularly to a shielding system for imshort circuits or arc-backs at elevated loads. It

has been found that, by providing suitable shields between the anode andv the container and be tween the anode and the active cathode surface,

"the arc-back rate may be materially decreased. @It has further been found that this improvement in arc-back rate is accompanied by an undesirable increase in arc drop. According to the present invention I have found that this increase in arc drop maybe offset by providing the end It is accordingly an object of my invention to provide, a vapor-electric valve of the makealive type having shields interposed between the anode surface and theactive cathode surface in order to prevent direct flow of vapor from the cathode to the anode surface and to so arrange the shields .that a plurality of arc paths are available,

I believe that one of the reasons for the improvement over heretofore known shields lies in the factthat the conducting vapor more readily enters the cathode space, so that less voltage is necessary to produce, the current-carrying arc.

' It is a further object of. my invention to pro- ;vide a. shield system permitting ready access of the working vapor into the arc space.

Other objects and advantages of my invention will be apparent from the following detailed descriptiontakenin. conjunction with the accompanying drawings, in which: I

Figure 1 is a sectional elevation of a vaporelectric device according to my invention; and

Fig. 2 is a similar illustration showing a modification according to my invention.

In the illustrated embodiment of my invention according to Fig. 1, the valve comprises an evacuated container, preferably of metal, having suitable means, such as a cooling coil 2, for maintaining the walls of the chamber l at a tem-=- perature at which the operating vapor of the device will be condensed. A pool of vaporizable material 3, such as mercury, or gallium, is pro shield l and the side shield 8.

vided, preferably in the bottom of the container l, and cooperating with this cathode pool 3 is a suitable anode 4 maintained in insulated relation to the container I. A make-alive electrode 5, that is, in an electrode composed of high resistant material, is positioned in permanent contact with the cathode material 3 so that a cathode spot may be formed thereon by passage of a suitable current through the make-alive electrode 5. i

In order to retain the cathode spot in a predetermined cathode area, a suitable baffle 6, such as quartz or porcelain, is anchored in the oathode material 3. While the baffle 6 may be mounted in any suitable manner, I prefer to float the baffle 6 in the cathode pool 3 and maintain it in position by means of a spider-like arrangement 1 which extends adjacent to the sides of the container l.

A suitable shield 8, preferably a tubular shield, is interposed between the sides of the anode 4 and the condensing side walls of the container l. While this shield 8 may be mounted in any suitable manner, I prefer to mount the shield upon the top of the container by means of a suitable insulating ring 9.

Interposed between the end of the anode 4 and the active cathode surface is a suitable end shield It]. This end shield is spaced from the end of the side shield 8 and preferably supported by suitable brackets H attached to the side shield 8 to provide a suitable arc space between the end The end shield 8 is preferably so proportioned that at no point can a straight line as shown at l3 from the active cathode surface intersect the inner surface of the side shield 8 or the surface of the anode 4.

In order to permit ready access of the mercury vapor to the arc space adjacent the anode surface, the end shield I0 is provided with an opening M, preferably adjacent the center thereof, and an auxiliary shield I is placed between the opening l4 and the anode surface '4. This auxiliary shield I5 is preferably so proportioned that a straight line such as Hi from any portion 'of the active cathode area passing through the opening M will intersect the auxiliary shield l5. This auxiliary shield l5 not only provides a passage for the access of working vapor to the arc space adjacent the anode surface, but also provides an additional arc space I! so that there are at least two parallel arc spaces l2 and I1 between the anode 4 and the active anode area .-3.

In the modification according to Fig. 2, the arc spaces l2 and 11 are further divided by suitable radial fins which serve as cooling means for rapidly cooling or deionizing the arc space at the end of each conducting half cycle through the device. If additional cooling is necessary, the fins may be extended to the Walls of the container, and, if desired, rigidly connected thereto in heat conducting connection, in which case, it will not be necessary to support the side shield upon the top of the container. Also, if desired, the fins 20 may be extended upwardly between the side shields and the condensing surface in order to provide a larger cooling area 20 to more quickly deionize the arc space.

While for purposes of illustration .1 have shown and described specific modifications according to my invention, it will be apparent to those skilled in the art that many changes and modifications can be made therein without departing from the true spirit of my invention and the scope of the appended claims.

I claim as my invention:

1. A vapor-electric valve comprising a container, a pool type cathode in said container, a resistance type electrode in contact with said pool type cathode during normal operation of said valve, an anode within said container cooperating with said cathode, a shield interposed between the sides of said anode and the container, an end shield interposed between the end of said anode and said cathode, said first and second mentioned shields being spaced to provide an arc space therebetween, said end shield having an opening therein, an auxiliary shield interposed between said opening and said anode, said auxiliary shield being spaced from said end shield to provide an arc space therethrough, and fins dividing said are spaces into a plurality of parallel paths.

2. An arc discharge device comprising a container, a pool type cathode .in said container, a make-alive electrode in permanent contact with said cathode, and anode cooperating with said cathode, an annular shield surrounding the sides of said anode, an insulating baflie for restricting the active cathode area to ;a predetermined portion of said pool type cathode, a shield interposed between said active cathode area and said anode, said shield having an opening adjacent the center thereof and a shield interposed between said opening and said anode, and a plurality of radial bafiies dividing the spaces between said shields into a plurality of parallel paths.

3. A vapor-electric valve comprising a metallic container, a pool of vaporizable cathode material in said container; an anode cooperating with said pool of cathode material, a make-alive electrode for periodically initiating a cathode spot on said pool of cathode material, means for retaining the cathode spot on a predetermined portion of the area of said pool of cathode material, means for cooling the walls of said container, a side shield interposed between the sides ofsaid anode and the wallsof said container, and end shield interposed between the end of said anode and the active area of said cathode pool, said end shield being spaced longitudinally from said side shield to provide a lateral, annular arc space therebetween, said end shield having an opening therein, an auxiliary shield between said anode and said opening, said auxiliary shield being spaced from said end shield to provide a second arc space.

4. A vapor-electric valve comprising a metallic container, a pool of vaporizable cathode material in said container, an anode cooperating with said pool of cathode material, a make-alive electrode for periodically initiating a cathode spot on said pool of cathode material, means for retaining the cathode spot on a predetermined portion of the area of said pool of cathode material, means for cooling the walls of said container, a side shield interposed between the sides of said anode and the walls ofsaid container, an end shield interposed between said anode and the active area of said cathode pool, said end shield being spaced from said side shield to provide an arc space therebetween, said end shield having an opening therein, an auxiliary shield between said anode and said opening, said auxiliary shield being spaced from said end shield to provide a second arc space, and radial fins between said end-shield and said side shield.

5. An arc dischargedevice comprising a container, a pool type cathode in said container, a make-alive electrode in permanent contact with said cathode, an anode cooperating with said cathode, an annular shield surrounding the sides of said anode, an insulating baffle for restricting the active cathode area to a predetermined portion of said pool type cathode, a shield interposed between said active cathode area and said anode, said shield-havingan opening adjacent the center thereof and a shield interposed between said opening and said anode, and a plurality of radial cooling baffles secured to said end shield.

6. A vapor-electric valve comprising an evacuated container, apool of vaporizable cathode material in said container, an anode cooperating with said pool of cathode material, means for periodically initiating a cathode spot on said pool of cathode material, an upstanding baiile for retaining the cathode spot on a predetermined .portion of the surface area of said pool of cathode material, means for cooling the walls of said container, a tubular side shield interposed between the side of said anode and the walls of said container, said side shield being closely spaced with respect to said anode, and end shield interposed between the end of said shield and the active cathode area, said end shield being longitudinally displaced from the end of the side shield to provide an arc passage therebetween, said end shield being of such diameter that a straight line from any point on the active cathodearea passing over the baflie and outside the end shield will not intersect the inner surface of the side shield, said end shield having an opening therein, an auxiliary shield spaced from the end shield and of such diameter that a straight line drawn from any point on the active cathode area through said opening will intersect the auxiliary shield.

WILLIAM E. PAKALA. 

